ASWING Summary

Analysis Capabilities

• Nonlinear static response, with arbitrary flight state specification
  • direct: specified angles, rates, control deflections
  • indirect: specified forces, moments, trim states
• Nonlinear dynamic response (time domain)
  • with or without arbitrary gust field
  • with or without arbitrary control forcing
  • with or without user-defined control law
  • evaluation via...
    • frame-by-frame plotting of all state quantities
    • aircraft-motion "movie"
• Linear dynamic response about nonlinear state (frequency domain)
  • due to...
    • Initial conditions,
    • Control forcing,
    • Gust velocity field
  • evaluation via...
    • Bode plots
    • Motion-response "movie"
    • Structural-response displays
• Eigenmode analysis
  • user-defined control law can participate (closed-loop stability)
  • entire frequency spectrum captured...
    • ..flight stability (lowest frequencies)
    • ..flutter stability (higher frequencies)
    • evaluation via...
      • root maps
      • motion eigenmode "movie"
      • structural eigenmode displays
    • Reduced Order Model construction based on selected eigenmodes

  Solution state for all analyses

  • structural deformations, angles (fully nonlinear)
  • structural loads, bending moments (general nonlinear 6-d.o.f. beam)
  • structural (local) velocities, rotation rates
  • circulation and lift distributions on all beams
  • aircraft position, and orientations
  • aircraft linear and angular velocities
  • aircraft linear and angular accelerations
  • control deflections (aerodynamic surfaces, engine power settings)

  Configuration Description

  • Interconnected nonlinear beams, representing aerodynamic...
    • lifting surfaces, or
    • slender bodies
  • Point objects with...
    • mass
    • angular momentum
    • drag area
    • volume
  • External struts
  • Engines with...
    • applied forces
    • applied moments
    • simple or advanced powerplant model
  • Control surfaces on beams, influencing...
    • section CL
    • section CM
  • General lifting-line aero representation, with...
    • wind-aligned trailing vorticity
    • wind-aligned Prandtl-Glauert compressibility treatment
    • section-stall lift limiting
    • section-stall profile drag model

  Software

  ASWING is licensed for commercial use by the MIT Technology Licensing Office
  (617) 253-6966

  Documents

• Theory document.
  asw_theory.ps (1061 Kb).
  asw_theory.pdf (420 Kb).
  
• Unsteady extension theory document.
  asw_uns_theory.ps (780 Kb).
  asw_uns_theory.pdf (330 Kb).
  
• Paper AIAA 99-1394, "Integrated Simulation Model for Preliminary Aerodynamic, Structural, and Control-Law Design of Aircraft."
  (condensed form of theory documents with a few application examples)
  asw_aiaa.ps (1520 Kb).
  asw_aiaa.pdf (460 Kb).
  
• Plain text version of User Guide.
  aswing_doc.txt
  
• ASWING runtime data flow organization. More detailed version of ASCII figure in User Guide.
  dataflow.ps
  dataflow.pdf
• Summary of changes made for recent ASWING versions.
  version_notes.txt

  Sample Input Files, Calculations

• Daedalus Human-Powered-Airplane.
  • Input file: dae.asw
  • Bode responses to rudder forcing: PDF plot
  • Response to 0.2 Hz rudder forcing, nearly rigid motion: (animated GIF, 1.7 MB)
  • Response to 1.0 Hz rudder forcing, reduced response due to tailboom compliance: (animated GIF, 0.7 MB)
  
  
• Ultralight Sailplane.
  • Input file: usa.asw
  • Specified vertical gust field: PDF plot
  • Nonlinear time-march solution: Vertical gust under left wing (animated GIF, 2.2 MB)
  
  
• Flying-Wing UAV
  • Input file: fw.asw
  • Eigenmode root progression with airspeed, showing Body Freedom Flutter (BFF) mode going unstable: PDF plot
  • Unstable BFF eigenmode movie: BFF mode (animated GIF, 4.4 MB)
  
  

  

  
  Numbers of unique visitors since 4 November 2007
  
  Gourmet Coffee

  Author: Mark Drela, drela (AT) mit (DOT) edu

  

  Page Revisions

  January 11, 2001
  - Page created. ASWING 5.42

  November 22, 2005
  - ASWING 5.62
  - Added the Sensor entity, which delivers state outputs
  - Added 2D-Bode frequency gust analysis
  - Added more general engine model capability
  - Added propeller plume model
  - Added structural damping
  - Added Reduced Order Modeling capability
  - ... and a bunch of other stuff. See version_notes.txt

  July 17, 2005
  - Added link to dataflow.ps file.

  March 10, 2007
  - ASWING 5.64
  - Further additions to the Reduced Order Modeling stuff.
  - ... See version_notes.txt

  March 13, 2007
  - Added PDF versions of PS documents

  October 25, 2007
  - ASWING 5.73
  - Added gust response info to the ROM output
  - Added ground effect
  - ... See version_notes.txt
  - Updated the theory documentation

  May 29, 2008
  - ASWING 5.79
  - Posted sample input files above
  - Lots of minor tweaks -- see version_notes.txt